A technology referred to as micro-machining and micro-electromechanics has emerged relatively recently as a result of advances in semiconductor technology, especially in the field of semiconductor processing. Micro-electromechanical systems (MEMS) are complex systems which individually include one or more electrical systems and one or more micromechanical systems. The micro-electromechanical systems are fabricated using many of the same fabrication techniques that have miniaturized electronic circuits and made mass production of silicon integrated circuit chips possible. Micro-electromechanical systems are typically made of silicon, polysilicon, silicon nitride and silicon dioxide on silicon wafers.
More specifically, utilizing fabrication techniques such as wet etching and photolithography, basic structures like grooves, holes, trenches, hemispheres, cantilevers, gears, and shafts, etc., can be built upon or within a silicon wafer. From these basic structures, a wide variety of micro-mechanical devices can be constructed. For example, among the numerous micro-electromechanical systems that have been successfully implemented are valves, springs, nozzles, printer heads, accelerometers, and chemical sensors. More complex devices, such as gas chromatographs, can be fabricated upon a silicon wafer a few centimeters in diameter.
In micro-electromechanical systems, a plurality of such electrical and micro-mechanical devices are integrated. For instance, a power supply, a micro-motor and a chemical sensor may be constructed on a single chip. These various different electrical and micro-mechanical devices may require different voltage levels to operate. Conventionally, these different voltage levels are provided by potential dividers or transformers. However, conventional voltage converters may not be fast enough for certain micro-electromechanical applications which require a relatively fast response time. Accordingly, a voltage shifter that is compatible with micro-electromechanical systems has been developed and is described in a U.S. patent application entitled Micro-Electromechanical Voltage Shifter, having Ser. No. 09/014,832, filed Jan. 28, 1998, now U.S. Pat. No. 5,889,389, issued Mar. 3, 1999, naming Jayarama N. Shenoy and Subhas Bothra as inventors, and incorporated herein by reference.
Some form of synchronization between plural systems may be desired inasmuch as mechanical and electrical systems are typically simultaneously operating within a micro-electromechanical system. Synchronization may be necessary for basic operation and/or for enhanced efficiency in operation of the micro-electromechanical system.
Therefore, the present invention provides devices and methodologies for providing synchronization in micro-electromechanical systems.